Dark brown Amanita

[bobby b]

Found in early July, Pgh PA, A. elongatior, nomen provisorum. Matches Mycoquebec second photo. Not as big as described but this was not fully matured. ??

https://mushroomobserver.org/458442

[Dave W]

It does look like A. elongatior; at least like some of the mushrooms that have been IDed as such. I have collected A. elongatior; DNA confirmed. Actually, specimens I sent to Rod Tulloss had been earmarked to represent a new taxon under a different species name, Amanita advenienticometa. Translated into English this means "arriving comet". If you look at the photos here https://mushroomobserver.org/169770?q=1lR0q you see that the specimen I found has a cap with a dark disc the darkly radiates in the form of innate fibrils. The impression this made on me was of viewing a comet with the debris tail streaming behind. I suggested this to Rod and he came up with "advenienticometa". As it turned out, the DNA matched that of collections made by Yves Lamoureux and previously provisionally named "elongatior". This species --like at least some others housed in section Vaginatae-- exhibits highly variable morphology. There are also very pale or even pure white specimens that are included within the species concept via DNA!  https://mushroomobserver.org/140066?q=1lR0q  . With some exceptions --eg. that very distinctive A. cremeosorora that you found and IDed--  IDing to species amanitas that represent section Vaginatae via morphology is basically impossible. 

Here's another one that resembles your dark-capped specimen, bobby  https://mushroomobserver.org/24793?q=1lR1c . Rod provisionally named this one after me! He says there are no sequences recorded that are close to the one derived from this mushroom. We're hoping that additional collections representing this taxon show up in the future. I've been looking... no luck so far. One difference I see is that my specimen appears to lack dark ornamentation on the stipe; so maybe yours is not the same species. But, if you find this dark type again, we would appreciate it if you preserve it for study. 

Your photos and care taken when harvesting are excellent. Maybe this one was gonna get bigger after expanding. But once a Vaginatae button pops out, the mushroom generally grows very quickly. 

[bobby b]

Thanks Dave. In the future I'll make an effort to preserve Amanitas that seem odd and post them.